There are X-ray imaging devices that take X-ray images via an imaging panel having a plurality of pixels. Japanese Patent Application Laid-Open Publication No. 2002-124676 discloses a technique whereby each pixel has a thin film transistor (TFT) and a photodiode, and X-rays passing through a specimen are converted to fluorescent light and then converted to electric charge by the photodiode, with the charge stored in the pixel being read out by operating the TFT. Each pixel has a bias line connected to a power source, and each pixel is connected to a photodiode.